Prefabricated trusses are often used in the construction of buildings because of their strength, reliability, low cost, and ease of use. The trusses are typically assembled in factories using automated machinery and large jig tables, and then shipped to construction sites for installation.
One known method for the assembly of trusses includes positioning truss members on the work-surface of a table within outlines projected upon the work-surface by an overhead laser light projection system. One such laser system is described in U.S. Pat. No. 5,388,318. An operator then moves jigging hardware into engagement with the truss members laid-out upon the work-surface to securely hold the members in place for subsequent assembly, e.g., embedding connector plates into the truss members to form the truss.
Using known laser systems, an operator typically sets-up a first portion of a truss upon a table work-surface and then secures the jigging hardware in place for that first portion. Once the first portion of the truss is secured by the jigging hardware, the remaining portions of the truss are sequentially set-up and secured, typically in a clockwise or counterclockwise order. This set-up approach is utilized because if the jigging hardware is incorrectly set-up for one portion of the truss, then the set-ups for all subsequently laid-out portions of the truss may be incorrect and have to be scrapped. By sequentially setting-up and securing the set-ups for the portions of the truss, the likelihood of having to scrap an entire set-up is reduced.
After fabricating one complete truss, the truss is removed from the work-surface and another truss of the same configuration can be assembled using the same jigging hardware set-up. Specifically, new truss members are positioned on the table according to the location of the jigging hardware, although the jigging hardware may require minor adjustment from one truss set-up to the next to ensure that the truss members are securely held in place.
The known laser projection systems greatly enhance the speed and precision of, and simplify, the set-up of truss members for factory assembly, as compared with manual systems and methods which depend upon the operator experience and knowledge in setting-up jigging hardware for truss fabrication. However, it would be desirable to provide a laser system and method which even further simplifies and speeds up the fabrication of trusses. It would also be desirable to provide a system and method which further reduces reliance upon operator experience and knowledge in setting up jigging hardware for truss fabrication.